Lens processing apparatus

ABSTRACT

Lens processing apparatus operable to remove lens blocks from a plurality of lenses and to completely clean the lens after dissolving the adhesive bond. A tub enclosure is adapted to receive one or more racks having notched lens engaging portions and an inclined block receiving portion. The tray is placed in the tub and sealed therein. The tub includes a heating element and a pump and spray arrangement for impelling a heated cleansing solution upwardly on the lens blanks and blocks. The adhesive, which may preferably be of low melting point metal, is dissolved and the blocks are released from the lenses to fall down onto the inclined bottom of the rack. The blocks roll to the lowermost portion thereof to a location that is out of the spray pattern. The solution may then be continuously applied to the lenses at the top of the tray to continue the cleaning cycle. The metal adhesive falls to the bottom of the tub into a sump configured to collect the liquid metal. A heated trap serves to allow the metal to flow exteriorly of the tub to be collected for reuse.

United States Patent [191 Reisman May 7, 1974 LENS PROCESSING APPARATUS clean the lens after dissolving the adhesive bond.

A tub enclosure is adapted to receive one or more racks having notched lens engaging portions and an inclined block receiving portion.

The tray is placed in the tub and sealed therein. The tub includes a heating element and a pump and spray arrangement for impelling a heated cleansing solution upwardly on the lens blanks and blocks.

The adhesive, which may preferably be of low melting point metal, is dissolved and the blocks are released from the lenses to fall down onto the inclined bottom of the rack. The blocks roll to the lowermost portion thereof to a location that is out of the spray pattern.

The solution may then be continuously applied to the lenses at the top of the tray to continue the cleaning cycle.

Primary Examiner-Richard A. Schacher Assistant ExaminerGene A. Church ABSTRACT Lens processing apparatus operable to remove lens blocks from a plurality of lenses and to completely The metal adhesive falls to the bottom of the tub into a sump configured to collect the liquid metal. A heated trap serves to allow the metal to flow exteriorly of the tub to be collected for reuse.

3 Claims, 7 Drawing Figures PATENTED MY 7 I874 SHEET 10F 3 PATENTED 7 I974 SHEET 2 [IF 3 FATENTEDm 7 m4 SHEET v3 0F 3 FIG. 5'

LENS PROCESSING APPARATUS BACKGROUND OF THE INVENTION The fabrication of lenses, such as eyeglass lenses, requires that a lens blank, of suitable configuration, be mounted on what is known as a block to which it must be firmly but removably attached for subsequent grinding and polishing operations as may be required, for example, by the prescription recommended by a refractionist. I

One common method for accomplishing the mounting of the lens on the block includes spraying of the surface of the lens to which engagement by the block is desired, with a soluble film and then injecting a metallic substance of substantially low melting point, i.e., less than the boiling point of water, through the block onto the coated surface of the lens while the block and lens are held in the suitable mold therefor.

In the prior art of which applicant is aware, the block was removed from the lens mechanically, then put into a tank of hot water where the alloy was reclaimed, then the lens itself was cleaned and dried manually. Various types of machines and apparatus have been attempted to perform this block removing and cleaning step, but none have thus far proven commercially successful. v

SUMMARY OF THE INVENTION My invention may be practiced or embodied in to be utilized in a specific manner to satisfactorily melt the adhesive to remove the blocks, completely and thoroughly cleanse the lens blanks and blocks and to recover the adhesive compounds for subsequent reuse for the purposes described above.

This is accomplished by disposing a plurality of lens blanks, each having a block adhesively secured'thereto, substantially at the top of a tub which is further provided with a fluid pump and spray assembly in proximity to the bottom. Admin for draining off melted or liq uified adhesive is disposed adjacent to the pump and baffles are mounted in proximity to the pump and to the drain to provide a separation between the melted immiscible adhesive and an aqueous-cleansing solution present in thetub so that the liquified adhesive may be drained off and reused.

It has also been discovered that it may be desirable to provide an inclined perforated surface that is transparent to the flow of fluidsfor receiving the blocks after the adhesive has been liquified and to direct them to a portion of the tub so that the blocks which have been removed will not interfere with the subsequent cleansing operation of the lens blanks.

These and other advantages of my invention will become apparent from a considerationof the appended specification, claims and drawings in which;

FIG. 1 is a side elevational view, partly in section, illustrating the arrangement of the several elements of a preferred embodiment of my invention;

FIG. 2 is a sectional view of the apparatus of FIG. 1, taken along section line 22 on FIG. 1 of the drawings;

FIG. 3 is a further sectional view of the apparatus shown in FIG. 1 taken along section line 3--3 of the drawings;

FIG. 4 is a fragmentary view partially in section taken along section lines 44 on FIG. 1 of the drawings;

FIGS. 5 and 6 are enlarged fragmentary views, partially in section, showing the relationship of a lens mounted upon a block with a preferred embodiment of a mounting rack therefor; and

FIG. 7 is a top elevational view of the fragmentary showing of FIG. 6 of the drawings.

Referring now to the several figures of the drawings, there is shown a lens processing apparatus indicated generally by reference character 10. Lens processing apparatus includes a housing 11, an interiorly mounted and disposed tub 12 having a downwardly disposed convex bottom 13; and a removable sealable cover member 14.

Tub 12 includes a suitable pump mechanism 16 disposed at the lowest portion thereof and approximately centrally located to rotatably support a spray arm 19 having generally upwardly directed openings therein.

Spray arm 19 is shown rotatable in a substantially horizontal plane generally about the vertical central axis of tub 12. Pump 16 may be energized from a suitable controlled source of electrical energy (not shown) or the like to pump fluid upwardly into spray arm 19 to thereby cause it to rotate and to completely spray the interior of tub 12 and cover 14 or to eject fluid from the bottom of tub 12 through a pump drain indicated generally by reference character 25. A heating element is shown in the form of a generally circular element 17 disposed concentrically around pump 16 and having terminals adopted for connection to a suitable source of controlled energization (not shown). A pump shield 20 disposed concentrically of pump 16 extends upwardly from the bottom 13 of tub 12, for a considerable distance toward spray arm 19.

An outer baffle 21 and an inner baffle 23 are concentrically disposed outside of pump shield 20 and are of considerably lesser height with respect to upwardly extending pump shield 20. Outer baffle 21 and inner baffle 23 also include a plurality of downwardly opening notches 22 and 24 respectively, on the lower edges thereof for purposes to be explained below. A sump shield shown in the form of a generally downwardly opening conical member 26, is mounted upon the lower portion of spray arm 19 and may vrotate therewith. The diameter of sump shield 26 is preferably greater than the diameter of outer baffle 21.

A drain 27, for liquified adhesive, is connected to an outlet 29 disposed at one of the lowermost portions of bottom 13 on tub 12 adjacent pump 16 and intermediate inner and outer baffles 23 and 21 respectively. Drain 27 is preferably formed with a suitable heater, 28, around the U-shaped portion. Heater 28 is adapted for connection to a suitable controlled source of electrical energy.

As illustrated in the top sectional view of FIG. 2, one or more trays, indicated generally by reference character 40, may be removably disposed in tub 12 so that lenses and blocks may be separated and cleansed. Tray 40 is shown including side portions 41 and 42, and end portions 43 and 44. One of the end portions, 44, has an aperture 45 which may be of suitable size and configuration to enable an operator to have access to the interior of the enclosure formed by the sides, ends and bottom of tray 40. A perforated, inclined bottom 46 is disposed on the interior of tray 40 and includes a notch portion 47 at the right end of FIG. 1 of the drawings, to receive and retain blocks which have already been separated from lenses held at the top of tray 40.

The top of tray 40 includes a plurality of parallelly disposed U-shaped rib portions 48, each having top and bottom portions. The top portions have a plurality of opposing notches, 49, and bottom portions have a plurality of opposing notches, 50, in slightly offset relationship in the manner shown in F IG. 7 of the drawings. Top notches 49 may be slightly deeper than bottom notches 50 so as to serve to retain a lens blank in position after a block has separated and fallen to the bottom, 46, of tray 40.

In FIGS. 6 and 7, a typical lens and block assembly is shown including a lens blank 54, a lens block 55, thin coating of parting material 56 on lens 54 and a volume of solidified adhesive securing one side of lens blank 54 to lens block 55.

It may be noted that the adhesive generally used for this purpose is a low melting point metallic compound or mixture that is immiscible in the cleansing solutions that may be used, one example being an aqueous solution including a suitable detergent. As may now be apparent to those skilled in the art, my invention procides an operative method and apparatus that will allow the use of any adhesive that has a greater density and is immiscible in a cleansing solution that may be used at a temperature above the melting point of the adhesive.

OPERATION In a preferred embodiment, a plurality of lens blanks, 54, which are adhesively secured to blocks .55 with quantities of low melting point metal 56, are disposed in the notches in ribs 48 at the top portions of tray 40. It is not essential that the entire top-of tray 40 be filled with lenses and blocks for separation and cleaning. One might, for example, have only a small number of lenses to be processed as is shown in the top view of FIG. 2. A suitable cleaning agent is added to the interior of tub 12 and water is added to the level indicated generally at the bottom of FIGS. 1 and 4.

Initially, heater 17 may be energized for whatever time is necessary to heat the liquid solution to a satisfactory temperature which will be dependent, to a great extent, upon the melting point characteristics of the metal which is utilized to bond individual lenses 54 to individual blocks 55. Following this, pump may be energized to cause the heated cleaning compound to be expelled through the top of spray arm 19 in a desirable pattern to project the heated cleaning fluid upwardly onto lenses and blocks 54 and 55. As the temperature of the lenses and blocks increased to the required level, the metal will become liquified and the adhesive and blocks will fall between ribs 48 on the top of tray 40 and downwardlyonto inclined expanded metal bottom portion 46. The blocks will be deflected toward the right end of the apparatus shown in FIG. 1 of the drawings so that the blocks will tend to collect in and around notch 47 formed in inclined expanded metal bottom 46 so as to eliminate the likelihood of obstructing the upwardly directed flow of fluid from the orifices disposed in the top of spray arm 19. Simultaneously, the liquified metal adhesive may drop downwardly onto the top of spray arm 19, the top of sump shield 26, and onto the bottom 13 of tub 12. Since the metal is of substantially greater density than the liquid aqueous washing solution, it will tend to remain on the bottom of tub 12 and to collect at the lowermost points thereon. Baffles 21 and 23 have notches provided at their lowermost peripheries, in engagement with the bottom of tub 13, so as to allow an unimpeded flow of fluid toward the metal outlet 29 on the bottom 13 of tub 12 at the location intermediate outer baffle 21 and inner bafile 23.

Pump shield 20 extends upwardly of the lower periphery of sump shield 26 and serves to establish the level of liquid washing solution in the bottom of tub 12. Pump shield 20 also serves as a further baffle to confine and separate melted metallic adhesive to the lowermost portion of bottom 13 on tub 12 and to tend to prevent liquified metallic adhesive from entering pump 15.

As the liquified metal accumulates in the bottom of tub 12, it tends to flow downwardly into metal drain 27 which is shown having a trap that is surrounded by a suitable heating element, identified by reference character 28. The heating element serves to maintain the metallic adhesive in a liquified condition so that it may flow freely through duct 27 and outwardly to a receptacle for collecting the same for reuse in securing lens blanks to lens blocks for the grinding and polishing operations to be performed thereon.

What is claimed is:

l. A support for holding lens blanks and blocks for separating and cleansing in a cleansing solution comprising in combination;

an enclosure having side and end walls;

a plurality of pairs of parallel ribs extending between the top portions of an opposing pair of side walls,

said ribs having upper and lower portions, said upper portion having opposing notches spaced to engage a lens blank and said lower portion having opposing notches spaced to engage and support a lens blank, said parallel ribs being spaced apart a distance sufficient to allow a lens block to fall therebetween; and

an inclined bottom portion that is substantially transparent to the flowof a cleansing solution extending between an opposing pair of said walls 2. The apparatus of claim 1 in which the inclined bottom portion includes a downwardly extending notch disposed adjacent the lowermostend.

3. The apparatus of claim 2 in which one of the walls of the support includes an outwardly opening access aperture. 

1. A support for holding lens blanks and blocks for separating and cleansing in a cleansing solution comprising in combination; an enclosure having side and end walls; a plurality of pairs of parallel ribs extending between the top portions of an opposing pair of side walls, said ribs having upper and lower portions, said upper portion having opposing notches spaced to engage a lens blank and said lower portion having opposing notches spaced to engage and support a lens blank, said parallel ribs being spaced apart a distance sufficient to allow a lens block to fall therebetween; and an inclined bottom portion that is substantially transparent to the flow of a cleansing solution extending between an opposing pair of said walls.
 2. The apparatus of claim 1 in which the inclined bottom portion includes a downwardly extending notch disposed adjacent the lowermost end.
 3. The apparatus of claim 2 in which one of the walls of the support includes an outwardly opening access aperture. 